单选题Performance monitoring of a poorly performing system indicates a high level of CPU usage. Which tool can be used to help identify which processes are using excessive CPU resources？（）A sarB topasC iostatD vmstat
题目
单选题
Performance monitoring of a poorly performing system indicates a high level of CPU usage. Which tool can be used to help identify which processes are using excessive CPU resources？（）
A
sar
B
topas
C
iostat
D
vmstat